Federer flies into Halle semi-finals

Roger Federer remains on course to lift a sixth title on the grass courts of Halle after the Swiss breezed past Mischa Zverev 6-0 6-0 in 39 minutes to reach the semi-finals.

It is only the second time the record 17-time grand slam champion has recorded a double bagel in his career, as the top seed was the first man to book his place in the last-four of the Gerry Weber Open.

Federer is looking to win his first title of 2013 having been to one final throughout the season - losing to Rafael Nadal at the Rome Masters - and ahead of the defence of his Wimbledon crown is in need of a trophy before arriving to SW19.

Federer stormed to the opening game by holding to love, and it was an early sign that he was in the mood to inflict damage on German wildcard Zverev.

Despite losing the first point in the following game, Federer won four on the spin to get the break, and consolidated it with a solid serve in the third game.

The fourth proved to be a tough one for Federer, but in the end the Swiss sealed a double break with a couple of fine backhand winners, and soon the opening set was in the bag in 20 minutes.

And the second set followed the pattern of the first as Federer played close to flawless tennis to march on at Halle.

"It's not something which is easy to do. You never go into a match aiming for that score," Federer said. "I was very surprised that it happened today, especially on grass."

Champion Tommy Haas is set to face Federer in a repeat of last year's final after the German came from a set down to overcome Gael Monfils 6-7(4) 6-3 6-3.

Second seed Richard Gasquet joined Federer in the last-four after the former Wimbledon semi-finalist got the better of Florian Mayer 6-3 7-6(4).